Stores

The History of ultrasound: Part 1

The History of ultrasound: From Bats and Boats to the Bedside and Beyond

The history of ultrasound starts with Lazzaro Spallanzani (1729–1799), an Italian physiologist and priest who designed a set of experiments to explain how bats were able to fly at night. By studying the bat’s ability to see and hear, Spallanzani noted that if a bat was blinded, it was still able to fly confidently through space; however, when a bat was made deaf, even in one ear, it could not fly safely in the experimental environment. On the basis of these findings, Spallanzani hypothesized that bats relied on sound, not their vision, to navigate. In 1938, two Harvard students, Donald Griffin and Robert Galambos, coined the word echolocation to explain how bats generate high-frequency clicks that bounce off surfaces and then receive and use the returned echoes to calculate the exact location of objects within their environment.